(1) Field of the Invention
The present invention relates to handheld devices for use in lung therapy through controlled inhalation and exhalation, and in particular to therapeutic devices that combine the functions of an incentive spirometer with a PEP breathing exerciser.
(2) Description of the Prior Art
Two handheld devices are commonly used in lung therapy exercises. The first of these devices, known as an incentive spirometer, is used in inhalation exercises to motivate the user in inhalation of a preset volume of air. The other type of the device, known as a PEP breathing exerciser or PEP breathing device, is used in exhalation exercises to help clear the lungs of mucus. Several different configurations of these devices are commercially available.
Generally, an incentive spirometer, sometimes referred to herein as a spirometer, is comprised of a chamber that is vented to the atmosphere and includes a ball or piston, and a breathing tube which has a proximal end in communication with the chamber and a distal end with a mouthpiece. In use, the patient inhales through the breathing tube to raise the ball or piston in the chamber. The chamber may be calibrated to indicate the amount of air being inhaled.
The spirometer may also include a second chamber or air source from which air is drawn into the breathing tube. This second chamber functions as a flowrate indicator. Its air circuit is also opened to the same inhalation gas stream with a smaller passageway for the stated purpose. By calibration, the rate of inhalation air critical to the opening of small airways at optimal conditions can be established.
PEP exercisers are used by patients to facilitate the removal of mucus in the lungs and strengthening the muscle tissues involved. A PEP exerciser is generally comprised of an exhalation tube that includes a resistor to airflow. The resistor may flutter or oscillate when air is expired, vibrating the airways to stimulate nerves and therefore promote coughing and loosening of mucus. The vibration may be created with a valve that is urged into a closed position with a spring or magnet, and temporarily opened by the force of exhalation.
Spirometers and PEP exercisers are sold as separate devices, although they are frequently used by the same patients. The need for separate devices for breathing exercises may add significantly to the cost of treatment. Keeping track of two devices is also inconvenient. Therefore, a separate breathing exercise device that functioned both as a spirometer and as a PEP exerciser would result in significant cost savings and convenience.